Sterile sampling methods and apparatus

ABSTRACT

An apparatus and method that allow multiple samples of a liquid in a primary container (here called a ‘pouch’) to be taken with minimal danger of contaminating the liquid in the container during the sampling process are disclosed. In an embodiment, a closed sterile sight chamber is connected with the pouch in a sterile manner to allow fluid to flow into the chamber while at the same time allowing air within the chamber to be displaced through a bacterial filter to atmosphere. The connection between the sight chamber and the pouch is then terminated (severed or closed), isolating the pouch from the sampling apparatus. Only then are samples of liquid withdrawn from the sight chamber, while allowing air to flow into the chamber through the bacterial filter.

CROSS-REFERENCE TO RELATED APPLICATIONS

The current application is a Continuation in Part of co-pending U.S.patent application Ser. No. 10/990,820, filed Nov. 17, 2004, whichclaims priority from Australian provisional patent application serialnumber 2003906364, filed Nov. 19, 2003.

FIELD OF THE INVENTION

This invention relates to methods and apparatus for the sterile samplingof liquids in containers in ways that minimize the danger ofcontaminating the liquid in the container by the sampling process. Itmay be applied to the sampling of platelets and other blood productsfrom collection pouches.

For convenience and without meaning to exclude other forms ofcontainers, the liquid containers to be sampled will herein be calledpouches. As it will be normal for the pouch being sampled to be arrangedabove the sampling apparatus to take advantage of the hydrostatic headthus provided, it will be convenient to refer to parts of the apparatusas being above or below, or as being upper or lower, with respect toother parts. However, the pouch and sampling apparatus could be arrangedso liquid flow does not flow under gravity, in which case some parts arelikely to be more distal or proximal relative to other parts (withrespect to the user). Accordingly, the terms ‘upper and ‘lower’, ‘above’and ‘below’ should be understood as being equivalent to ‘distal and‘proximal’ (respectively) as used herein.

BACKGROUND OF THE INVENTION

There are occasions in medical practice where it is desirable to checkthe sterility or other properties of a liquid stored in a pouch beforethat liquid is administered to a patient or otherwise used. Examples areblood and blood components such as serum and platelets. The US bloodindustry association, the American Association of Blood Banks (AABB), anassociation that is globally recognized, recently updated the technicalrequirements for blood collection, storage and testing and has includeda new pre-transfusion QC requirement that will go into effect in March2004. The new QC test requirement involves testing stored platelets forevidence of bacteria. If bacteria are detected in a unit (i.e., a pouch)of platelets, that unit will not be eligible for transfusion. In orderto perform the necessary tests, multiple samples of platelets areusually extracted from the platelet container into respective samplephials. In some cases samples from multiple pouches are mixed and thentested. However, there is serious danger that the sampling procedureitself can introduce bacteria into the pouch liquid.

The pouches usually have attached plastic filling tubes that have beenheat-sealed. To take a sample, a sharp hollow steel needle attached to asyringe can be inserted into the filling tube and some of the liquidwithdrawn before the needle pulled out of the tube. Desirably, thefilling tube can be heat-sealed again between the pouch and the puncturepoint. Some pouches are provided with ‘needleless ports’, which haveseptums that can be penetrated by blunt cannulae attached to syringes.In either case, bacteria can be introduced into the pouch during thesampling process and/or by subsequent entry through the puncture site.The use of a blunt cannular with a needleless port not risks introducingbacterial into the pouch but it normally does not allow for subsequentheat-sealing to isolate the port. Of course, collecting samples by usinga needle to puncture the thin wall of the pouch itself offers the worstalternative because of the likelihood that, after withdrawal of theneedle, the thin wall of the pouch will not seal sufficiently to preventthe ingress of bacteria through the puncture site.

SUMMARY OF THE INVENTION

The present invention provides methods that allow multiple samples of aliquid in a primary container (here called a ‘pouch’) to be taken withminimal danger of contaminating the liquid in the container during thesampling process. The method involves connecting a closed sterile sightchamber with the pouch in a sterile manner to allow fluid to flow intothe chamber while at the same time allowing air within the chamber to bedisplaced through a bacterial filter to atmosphere. The connectionbetween the sight chamber and the pouch is then terminated (severed orclosed), isolating the pouch from the sampling apparatus. Only then aresamples of liquid withdrawn from the sight chamber, while allowing airto flow into the chamber through the bacterial filter. Though there maystill be risk of contamination of liquid in the sight chamber as samplesare withdrawn, such contamination cannot carry through to the liquid inthe pouch.

Where the pouch is provided with a sealed flexible thermoplastic outlettube, a similar inlet tube is connected to the chamber and a connectionbetween the outlet tube and the inlet tube is preferably effected by‘sterile-docking’ the outlet tube and the inlet tube to establishsterile connection therebetween. [Sterile-docking is a known techniqueand is disclosed, for example, in U.S. Pat. No. 4,369,779 to DuPont.]However, the method of the invention preferably includes the steps ofclosing (e.g., by clamping) the inlet tube below the point where thesterile-docking is to take place, releasing the clamp after thesterile-docking has been effected to allow a quantity of liquid to flowfrom the pouch to the chamber, re-closing the inlet tube to stop liquidflow and then heat sealing both the pouch outlet tube and the chamberinlet tube (allowing the docked portion of these tubes to be discarded).Alternatively, where the pouch is only provided with a septum port, thechamber inlet tube can be fitted with a blunt-tipped cannular adapted toenter that port to establish the connection between the pouch and thechamber in a substantially sterile manner. While the clamping andunclamping procedure just indicated can also be followed with advantage,the connection between the pouch and the sight chamber should beterminated by withdrawing the cannular before samples are drawn-off fromthe sight chamber.

The method may also include entering evacuated sample phials into acup-like sample port (which has a sheathed needle that is connected tothe chamber) to effect the withdrawal of portions of the liquid in thechamber as separate samples. Since the needle is sheathed, the outlet ofthe sight chamber is sealed until the first sample is taken so there isminimal danger of contamination of the pouch liquid via the chamber.Since all samples are drawn-off while the chamber is disconnected fromthe pouch, there is no danger that the sample gathering procedure willcontaminate the liquid in the pouch and there is only a very slightdanger that the sampling procedure will contaminate liquid within thechamber or the samples. The sample port can be rigidly attached to thesample chamber so that the chamber can be held vertical and in view bygripping the sample port in one hand while inserting successive filesinto the port with the other hand.

The sight chamber can be conveniently formed from the transparent barrelof a medical syringe having volume graduations so that the amount ofliquid withdrawn in each sample can be judged and controlled. Though theuse of a flexible-walled bag-like chamber is also envisaged, it is notpreferred.

As liquid may flow into the chamber too quickly when the pouch isconnected, or be may be withdrawn too quickly from the chamber when aphial is inserted into the sample port, the method may include the stepof at least partially closing the chamber vent to regulate the rate ofegress or ingress of air from and to the chamber. A hinged cap may beprovided for closure of the chamber vent and can be used for thefunction indicated. Of course, the rate of inflow of liquid from thepouch to the chamber can also be regulated by the use of a clamp valvefitted to the inlet tube.

From another aspect, the invention comprises apparatus for use indispensing samples of liquid drawn from a pouch in a sterile manner, theapparatus including a sight chamber with inlet means, such as theaforementioned thermoplastic inlet tube, for conveying liquid from thepouch to the chamber under sterile conditions. The chamber also hasoutlet means adapted to permit flow of liquid from the chamber in one ormore samples. A filtered vent is provided in the chamber to permitdisplaced air to flow from the chamber when liquid flows therein and topermit air to flow into the chamber when liquid flows therefrom, thefiltered vent serving to block passage of airborne particles includingbacteria into the chamber. Valve means (such as a tube clamp) can beprovided in association with the inlet means to control flow of liquidinto the chamber and also to isolate the chamber from the pouch.

The sample dispensing means is preferably the aforementioned sampleport, which is preferably rigidly connected to the lower end of thesight chamber. The sheathed needle of the sample port preferably has athreaded hub by which it is screwed into the closed end of the sampleport from the outside, the needle hub preferably being inhibited fromunscrewing by ratchet means operable between the hub and the closed endof the port. The sample port may have a hinged cap for closing the openend against accidental intrusion of the finger of a user into contactwith the needle point.

The cap preferably includes locking means whereby it can be held closedafter use of the sample port and, if necessary, reopened for theinsertion of another phial or bottle. The locking means can comprise atab or catch on the cap that engages with a hole or abutment on the bodyof the port, or it may comprise flanges on the cap and body that engagewith one another in the manner of the catch of a purse.

The apparatus may include a tubular spacer that slidingly fits into theopen end of the sample port for the purpose of guiding phials that areof much smaller diameter than the port. The spacer may include radiallyextending tabs by which it may be gripped between a thumb and finger ofa user so that these digits cannot enter the sample port when the spaceris inserted. The spacer is adapted to clip to or snap onto or into thesample port, preferably in such a way that it can be removed from theport (if desired) by again holding the tabs between thumb and finger.

Apparatus of this type may be incorporated in products by manufacturersof blood collection packs, aphaeresis kits, urinary catheter kits,plural and abdominal cavity aspiration kits and the like. In suchapplications the inlet tubes would be attached by the manufacturer tothe kits and it would not be necessary for the user to make the initialconnection. However, it may be preferred to employ a frangible connectorin the inlet tube to effect the initial connection between the source ofthe sample liquid and the sterile sampling apparatus of the presentinvention. In one particular application, the inlet tube, chamber andsample port may be attached to the platelet pouch of an aphaeresis kitby the kit manufacturer without the need for separate sterile packaging.The port would then be immediately ready for use in drawing samples fromthe pouch without the need for separate sterile docking procedure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a conventional blood or platelet pouch.

FIG. 2 is a perspective view of the sampling apparatus of the preferredembodiment.

FIG. 2A is an enlarged perspective sectional view of the sample port ofthe apparatus of FIG. 2 taken on section plane II-II of FIG. 2.

FIG. 3 is a side elevation of the apparatus of FIG. 2 with the principalcomponents shown separated from one another, the sample port also beingshown in section, the section plane being indicated at II-II in FIG. 2.

FIG. 4 is a perspective view of the apparatus of FIGS. 1-3 modified in afirst way that allows the use of a blunt cannular to access aseptum-port in the pouch to be sampled.

FIG. 4A is an enlarged view of the blunt cannular used in the modifiedapparatus of FIG. 4.

FIG. 5 is a perspective view of the apparatus of FIGS. 1-3 modified toallow samples from multiple pouches to be obtained and mixed beforebeing dispensed to sample phials.

FIG. 6 is a perspective view of the sample port of the apparatusillustrated in the previous Figures and a spacer element for usetherewith.

FIG. 7 is a perspective view of the sample port of FIG. 6 with thespacer element inserted into the sample port.

FIG. 8 is a side view of a further embodiment of the invention.

FIG. 9 is another side view of the FIG. 8 embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a liquid container comprising a conventional sealed plasticpouch 10 containing a unit of platelets liquid, generally indicated at12. Pouch 10 may have blanked-off tube connections 14 that may have beenused during collection of the platelets but it will generally have atleast one attached outlet or pouch tube 16 that is heat-sealed at itsfree end 17. Pouch 10 may also be provided with a split-septum needlessport 18 through which a hollow blunt cannular can be inserted to extractsamples of liquid 12. Samples of liquid may also be drawn from tube 16by the use of a syringe and sharp medical needle. As already noted, boththese methods of withdrawing samples involve contamination risk, both tothe extracted sample and to the liquid in the pouch.

Turing now to FIGS. 2, 2A and 3, the apparatus 50 of the preferredembodiment will now be described. Apparatus 50 is preferably supplied asa sterile unit. It has a plastic inlet or sample tube 52 that is that isheat-sealed at its free upper (or distal) end 54 and is fitted with apinch clamp 55, which is shown in the open position in which tube 52 isnot pinched or blocked. Apparatus 50 also includes a tubular transparentand semi-rigid sight chamber 56 that has an open upper or distal end 57closed by a closure 58 that has a first tubular spigot 60 connected tothe lower or proximal end 62 of sample tube 52 and a second tubularspigot 64 that forms or is connected by a short tube 65 to a filter 66though which chamber 56 can be vented to atmosphere. Filter 66 is fittedwith bacterial filter media (not shown) that allows air to pass butblocks the passage of bacteria, such filter media being known in the artand being commercially available. Preferably, a hinged cap 67 isattached to filter 66 so that the open end of filter 66 can be sealed,if desired.

Sight chamber 56 is conveniently formed from the transparent barrel of aconventional medical syringe that has appropriate volume graduations 68and a tapered lower or proximal end 70 that terminates in an externalspigot-like female Luer socket 72.

A sample port assembly 80 is rigidly connected to Luer socket 72, portassembly 80 comprising (i) a cup-like hollow cylindrical body 82 havinga closed upper or distal end 84 and an open lower or proximal end 86 and(ii) a sampling needle assembly 88 (FIG. 2A) screwed into upper end 84of body 82 so as to extend coaxially therein. Body 82 is preferablymolded from plastic with an integrally hinged cap 90 attached to itslower or proximal end 86. Hinged cap 90 is provided with a locking tab92 that engages with a slot 94 in the side of body 82 so that the cap 90is held in the closed position to prevent inadvertent contact betweenthe fingers of a user and needle assembly 88 in body 82. Lower end 86 ofbody 82 and the periphery of cap 90 are provided with outwardlyextending flanges 96 and 98 respectively by which the cap can readilypried open again, if desired, between the user's finger and thumb.

Referring particularly to the enlarged drawing of FIG. 2A, samplingneedle assembly 88 comprises a pointed hollow steel needle 100 that issurrounded by a rubber-like sheath 102 and is supported by a moldedexternally threaded hub 104 having an upper or distal end 106 formedwith a distal male Luer spigot 108 (see FIG. 3). Male Luer spigot 108engages with female Luer socket 72 to form a rigid connection betweensample port assembly 80 and sight chamber 56. Hub 104 is screwed into ahollow boss 110 formed in distal or upper end 84 of body 82.

The assembled sampling apparatus 50 is normally shipped as a unit in asterile pack with vent cap 67 and port cap 90 closed. This minimizes thedanger that the edges of the caps will penetrate the packaging duringhandling. The supply of apparatus 10 with vent cap 67 closed allowssight chamber 56 to remain sealed to atmosphere until sample tube 52 hasbeen docked with pouch tube 16. Similarly, the supply of apparatus 50with port cap 90 closed ensures that a finger of a user cannot enterport 56 while apparatus 50 is being handled or coupled to pouch 10. Suchcontact would be likely to cause the point of needle 100 to puncturesheath 102 thus breaking the seal to the chamber via its outlet. Pinchclamp 55 is normally fitted in the open position so that the risk ofpermanently kinking inlet tube 52 is minimized.

To ready the assembly 50 for use after removal from its pack (notshown), caps 67 and 90 are opened and clamp 55 is closed. Inlet orsample tube 52 is then placed along side pouch tube 16 in a sterileclocking jig, the preferred area for sterile docking being indicated byspaced markings 112 on sample tube 52. The sterile docking procedure isthen performed in the normal manner, simultaneously cutting off thesealed ends of tubes 16 and 52 and connecting the severed ends of thesetubes together for fluid communication (as described above). Clamp 55and vent cap 67 are then opened to allow the desired amount of liquid toflow from pouch 10 into sample chamber 56, after which clamp 55 isclosed to stop further flow. Flow of liquid 12 from pouch 10 willnormally occur under gravity and/or with slight pressure on pouch 10,the flow being assisted by the open vent 66 that allows the air withinsight chamber 56 to be displaced. Hence, apparatus 50 will normally bearranged substantially vertically and below pouch 10, with sample tube52 uppermost and sample port 80 lowermost. This allows the amount ofsample liquid in sight chamber 56 to be accurately determined byreference to graduations 68 before clamp 55 is operated to close sampletube 52. Preferably, at this stage, pouch tube 16 is heat-sealed andsevered above the docking point and sample tube 52 is heat sealed andsevered below the docking point, the docked connection then beingdiscarded. This keeps sampling apparatus 50 sealed and sterile duringcollection of the sample liquid in sight chamber 56, except for theegress of displaced air though bacterial filter 66. Sample port cap 90is then prized open by using flanges 96 and 98 to ready apparatus 50 fordispensing of individual sample portions of the sample liquid held insight chamber 56.

With assembly 50 held generally vertically, preferably by grippingsample port 80 in one hand, vacuum bottles or phials (not shown) areentered upwards into body 82 from open lower end 86 and pushed ontosheathed needle assembly 88 so that needle 100 pierces the sheath 102and passes through the soft bung of the bottle or phial to suck portionof the liquid in chamber 56. As soon as the desired amount of liquid hasbeen removed, the bottle or phial is pulled from needle assembly 88 andsample port 80, leaving sheath 102 to re-cover needle 100. Successivesamples can be quickly and conveniently taken in this way usingsuccessive phials or bottles. If desired, port cap 90 can be moved tothe closed position between each sample.

Where a liquid with lower viscosity than platelets, or where a largegauge sampling needle 100, is employed, the flow of liquid from sightchamber 56 to the sample phial or bottle may be too fast to accuratelyjudge the portion required for each phial. The flow rate can be reducedby at least partially closing the opening of vent 66 with a finger orthumb or with cap 67. When sufficient samples have been extracted, orwhen chamber 56 has been emptied, assembly 50 can be discarded using anappropriate disposal container. Before doing so, however, port cap 90should be snapped closed to mitigate possible contact between a fingerof the user and needle 100 and vent cap 67 should be closed to preventseepage of liquid from the vent.

Turning now to FIGS. 4 and 4A that illustrate a modified samplingapparatus 200 that is very similar to as apparatus 50 described aboveexcept for some particular modifications. Accordingly, those parts ofapparatus 200 that are essentially the same as those of apparatus 50have been assigned the same reference numerals. The first importantmodification is a blunt cannular 202 fitted to the upper or distal endof sample tube 52 instead of heat-sealed end 54. The cannular tip 204 isof conventional design (and is shown greatly enlarged in FIG. 4A) havingside inlet apertures 206 and a non-coring nose 207. The second importantmodification is in the way that port cap 90 is locked closed. In thiscase locking tab 92 is omitted together with cooperating slot 94 and thelateral flanges 96 a and 98 a on open end 86 of port body 82 and on cap90 (respectively) are modified so that they can snap together in theclosed position like the closure commonly used in ladies purses. Theomission of tab 92 simplifies the molding procedure and the omission ofslot 94 reduces the possibility of liquid dripping from port body 82.

A third modification comprises the use of a ratchet-like engagementbetween the radial face of Luer needle hub 92 and the radial face of aboss 110 on the closed upper end 84 of port 80 in such a way as toinhibit unscrewing of needle assembly 88. In this case, ratchet teeth210 are formed on the radial face of boss 110.

Another optional modification to apparatus 50 and/or 200 described aboveis embodied in apparatus 220 of FIG. 5, which apparatus has manycomponents common to the foregoing apparatus, such components againbeing assigned the same reference numerals. The first modificationembodied in apparatus 220 is the replacement of former inlet or sampletube 52 by four sample tubes 52 a, 52 b, 52 c and 52 d, each having aheat sealed distal end (54 a, 54 b, 54 c and 54 d, respectively) andeach having its own clamp (55 a, 55 b, 55 c and 55 d, respectively). Thelower or proximal ends of tubes 52 a, 52 b, 52 c and 52 d are coupled bya four-way connector 222 to inlet spigot 60. Multiple inlet or sampletubes 52 a-52 d are provided so that liquid can be extracted fromrespective multiple pouches into common sight chamber 56 and mixedtherein before being dispensed to one or more sample phials (not shown)without any possible danger of cross contamination between pouches.

Thus, the advised procedure for generating a mixed sample from multiplepouches is to close all clamps 55 a-55 d, sterile dock a first pouch to,say sample tube 52 a, release clamp 55a to allow a first quantity ofliquid to flow from the first pouch to sample chamber 56, close clamp 55a, heat-seal and sever the outlet tube of the first pouch, heat-seal andsever inlet tube 52 a above clamp 55 a, and then repeat these steps foreach pouch and each sample tube (52 b-52 d) in turn. Thus, at no timewould more than one pouch be connected to the apparatus and no outlettube of a pouch would be docked to a used inlet tube of the apparatus,so cross-contamination between the pouches would be excluded. A possiblebut less desirable procedure would be to connect more than one pouch tosight chamber 56 via respective inlet tubes 52 a-52 d and to operaterespective clamps 55 a-55 d, ensuring that only one clamp was open atone time.

The second modification embodied in apparatus 220 illustrated in FIG. 5is the use of a large diameter filter housing 66 a connected to spigot64 via an elbow connector 224. The larger housing 66 a allows the use ofa filter element (not shown) of larger area to provide less restrictedair flow and, consequently, to permit more rapid in-flow of liquid intochamber 56 and more rapid draw-off of samples using vacuum phials. Thethird modification embodied in apparatus 220 relates to sample port 80 aand will be described with reference to FIGS. 6 and 7.

FIGS. 6 and 7 show modified sample port 80 a adapted for use with askeletal molded plastic spacer element 250 of generally tubular formthat can be pushed upward (as indicated by arrow 252) into body 82 of amodified sample port 80 a to allow narrow diameter phials to be reliablyaligned with needle assembly 88, larger diameter bottles or phials beingaligned by the walls of the port body itself. Spacer element 250 isprovided with two radial outwardly-extending tabs 254 on its lower orproximal end 256 and open end 86 of port body 82 is provided with aradial outwardly-extending flange 258 having a pair of opposed notches260 therein, each notch 260 being proportioned to accommodate respectiveones of tabs 254 in a snap fit. The use of outwardly extending tabs thatengage the rim portion of open end 86 of port 80 a allows spacer element250 to be inserted by holding it between thumb and finger in such a waythat contact between either digit and needle assembly 88 (or theinterior of body 82) is strongly inhibited. It will be noted from FIGS.6 and 7 that sample port cap 90 employs the purse-type snap closuredescribed with respect to FIG. 4, which has inter-engaging radial tabs96 a and 98 a on open end 86 of port body 82 and on cap 90(respectively).

Normally, the user of sampling apparatus having modified sample port 80a and associated spacer 250 will use either large or small diameterphials and, if small diameter phials have been selected, will insertspacer element 250 before the apparatus is connected to pouch tube 16.However, there are occasions where the user is required to collectsamples in both small and large diameter phials. This may benecessitated by the destined use of the sample phials or by the type ofmachines to which they will be coupled. In that event, the user willtransfer sample(s) to the large phial or phials before fitting spacerelement 250 and, after fitting spacer element 250, then transfersample(s) to the smaller phial or phials. In the event that a mistake ismade and spacer element 250 is inserted before all large diameter phialshave been filled, the user can remove spacer element 250 by gripping theedges of tabs 254 and squeezing them together to unlatch them from theirrespective notches 260. Again, it will be noted that this action iseffected without the need for the user to put a finger into spacer 250or body 82 of port assembly 80.

Referring to FIGS. 8 & 9 there is shown an assembly 300 according to afurther example of the invention. The assembly 300 comprises a combinedpouch 310 (typically a platelet container), sight chamber 312 andsampling port 316 arrangement. The pouch 310 is connected to a sightchamber 312 via tube 314. Sampling port 316 is mounted on outlet 318 ofsight chamber 312. The sight chamber 312 and sampling port 316 aresubstantially as the sight chamber 56 and sampling port 80 as shown inFIGS. 2 to 4 a, albeit having a large diameter filter housing 320similar to filter housing 66 a of FIG. 5. The sampling port 316 may beused with the spacer element 250 shown in FIGS. 6 and 6 a.

A tube clamp 322 is located on the tube 314 intermediate the pouch 310and sight chamber 312.

The arrangement 300 is manufactured with the tube connected to the pouch310 and sight chamber 312 such that the end user does not need to makethe initial connection between the pouch 310 and the sight chamber 312.During manufacture the arrangement is sterilised. The sampling port maybe provided attached to the sight chamber or may be provided in aseparate sterile package for attachment by the end user on the outlet ofthe sight chamber.

As supplied to the end user the tube clamp is preferably closed and soblocks tube 314. Accordingly, until such time as the tube clamp 322 isopened contamination cannot transfer from the sight chamber 312 to thepouch 310. However, a frangible barrier 323 may be provided in the tube314 that initially closes the tube.

The pouch is filled with a fluid, typically a concentrated plateletsmixture derived from whole blood. The exact nature of the fluid is notimportant and, for example, the arrangement may be used with wholeblood.

With the tube clamp 322 or frangible barrier 323 closed the fluid cannottransfer to the sight chamber.

For testing of the fluid in the pouch the assembly is preferablyarranged vertically, with the pouch above the sight chamber, as in FIG.9. Typically this may be achieved by hanging the pouch from a hook orsimilar via opening 324. The sight chamber 312 and sampling port 318hang from the pouch. The sight chamber need not hang directly below thepouch and may be raised by a user.

The tube clamp 322 is opened or the frangible barrier 323 opened andfluid flows from the pouch to the sight chamber via tube 314. The amountof fluid 326 in the sight chamber may be measured against graduations328. As fluid 326 enters the sight chamber air in the sight chamberexits via filter 320.

As seen in FIG. 3, the inlet 330 does not extend downwards from cap 332significantly and so an air gap 334 may be maintained between the top336 of the fluid passed into the sight chamber and bottom of the inlet330. Thus any contamination cannot pass via the fluid in the sightchamber back up the tube 314 to the pouch 310.

When sufficient fluid has passed into the sight chamber 312 the tubeclamp 322 is closed, isolating pouch 310 from sight chamber 312. Ideallythe tube is heat sealed between the tube clamp 322 and pouch 310, asindicated by 338 before any fluid is removed from the sight chamber. Oneor more samples are taken from the sight chamber by passing one or morevials into the sampling port and impaling the vial on the needle 100(shown in FIG. 3) as previously described.

While a preferred embodiment of the invention has been described andillustrated together with some variants, it will be appreciated by thoseskilled in the art that many other changes can be made without departingfrom the scope of the present invention as defined by the followingclaims.

1. A method for providing at least one sample of liquid from a quantityof liquid contained in a pouch while mitigating the danger ofcontaminating the liquid in the pouch, the method comprising:establishing a sterile fluid connection between the pouch and an inlettube having proximal and distal ends, the proximal end connected to aninlet of a sterile sight chamber, the chamber comprising: a vent fittedwith a bacterial filter through which air can flow to and from thechamber; and an outlet; the inlet tube comprising a tube clamp thereon,wherein the connection is established distal to the tube clamp; afterestablishing the connection, opening the tube clamp and allowing aquantity of liquid to flow into the chamber from the pouch while ventingdisplaced air from the chamber through the vent; closing the tube clampto prevent fluid flow between the pouch and the chamber; after closingthe tube clamp, terminating the connection between the pouch and theinlet tube; and after terminating the connection, withdrawing at leastone sample of liquid from the chamber into at least one sample phialwhile allowing air to enter the chamber via the vent to replace theliquid withdrawn.
 2. The method of claim 1, wherein the pouch comprisesa sealed flexible thermoplastic outlet tube, and the inlet tubecomprises a flexible thermoplastic inlet tube, and wherein saidestablishing a sterile fluid connection between the pouch and the inlettube is performed by: clamping the inlet tube to block flow of liquidtherethrough; sterile-docking the inlet tube with the outlet tube toprovide a sterile fluid connection therebetween; and unclamping theinlet tube to permit flow of liquid from the pouch to the chamber; andsaid terminating the connection is effected by clamping the inlet tubeto block further flow of liquid into the chamber and then heat-sealingthe outlet tube from the pouch.
 3. The method of claim 1, wherein thevent has an opening to the environment, the method additionallycomprising: restricting the vent by partially covering the opening torestrict flow of air from the chamber when liquid is flowing into thechamber so as to limit the rate of fluid flow and to thereby facilitatethe termination of the connection between the pouch and the chamber whena desired amount of liquid has flowed into the chamber.
 4. The method ofclaim 1, wherein the sight chamber is marked with graduations toindicate the volume of liquid therein, wherein the vent has an openingto the environment, and wherein the method additionally comprises:restricting the vent by partially covering the opening to restrict flowof air into the chamber when said at least one sample is being withdrawnso as to slow the rate of withdrawal of liquid from the chamber, therebyfacilitating termination of said withdrawing step when a predeterminedvolume of liquid has been withdrawn from the chamber into the samplephial, as indicated by reference to said graduations of the chamber. 5.The method of claim 1, wherein a cup-like sample port having an open endand a tubular peripheral wall is connected to the outlet of the chamber,the sample port has an internal diameter adapted to receive a firstsample phial having an external diameter approximating the internaldiameter of the sample port, and the method additionally comprises:inserting a tubular spacer into the sample port, the tubular spacerhaving an internal diameter adapted to receive a second sample phialhaving an external diameter substantially smaller that the externaldiameter of the first sample phial; and inserting the second samplephial into the spacer and sample port, and withdrawing a sample ofliquid from the chamber into the second phial.
 6. Apparatus forproviding at least one sample of a liquid contained in a pouch whilemitigating the danger of contaminating the liquid in the pouch, theapparatus comprising: an inlet tube having proximal and distal ends,wherein the distal end is closed, and the proximal end is connected toan inlet of a sterile sight chamber, the chamber comprising: a ventfitted with a bacterial filter through which air can flow to and fromthe chamber; and an outlet; the inlet tube comprising a tube clampthereon, wherein the tube clamp is a sufficient distance from the distalend to permit a sterile fluid connection to be established with theinlet tube at a point distal to the tube clamp; and the tube clampoperable to regulate liquid flow through the inlet tube to the chamberwhen the connection is established and operable to block fluid flow inthe absence of the connection.
 7. Apparatus according to claim 6,wherein the inlet tube comprises a flexible thermoplastic inlet tube. 8.Apparatus according to claim 7, additionally comprising: a cup-likesample port having an open end and a tubular peripheral wall fordispensing liquid in the chamber into at least one sample phial in asubstantially sterile manner, wherein the sample port is connected tothe outlet of the chamber; the sample port having an internal diameteradapted to receive a first sample phial having an external diameterapproximating the internal diameter of the sample port; and a tubularspacer having an internal diameter adapted to receive a second samplephial having an external diameter substantially smaller than theexternal diameter of the first sample phial; the spacer being adapted tobe slidably received within the sample port, and the spacer having alower end; a clip for clipping the spacer into the sample port when thespacer is received therein; opposed tabs on the lower end of the spacer,the tabs adapted to extend radially outwards from the open end of thesample port when the spacer is received therein; and the tabs areadapted to be gripped between a thumb and finger of a user for insertionof the spacer into the sample port so that neither the thumb nor fingerenter the sample port during insertion of the spacer into the sampleport.
 9. Apparatus according to claim 7, wherein: the sight chamber istubular and transparent and has an upper end and a lower end; the inletis located at the upper end, and the outlet is located at the lower end;the sample port is joined to the outlet in a rigid manner so that thesight chamber can be supported substantially upright by a user holdingthe sample port in one hand while inserting a phial into the open end ofthe sample port with the other hand.
 10. The method of claim 1, whereinthe liquid comprises blood, blood serum or blood platelets.
 11. Themethod of claim 1, wherein: the sight chamber is tubular and transparentand has an upper end and a lower end; the inlet is located at the upperend and the outlet is located at the lower end; the vent is located atthe upper end; the sight chamber is marked with graduations to indicatethe volume of liquid therein, the uppermost of the graduations beingbelow the inlet and vent; the method comprises maintaining the sightchamber substantially vertical with the upper end above the lower end,and filling a minor quantity of the liquid to one of the graduations,thereby maintaining an air gap between the liquid in the sight chamberand the inlet during said allowing a quantity of the liquid in the pouchto flow into the chamber; and maintaining the sight chambersubstantially vertical with the upper end above the lower end whilewithdrawing the at least one sample.
 12. The method of claim 1, whereinthe chamber is transparent and rigid.
 13. The method of claim 1, whereinsaid at least one sample flows into said at least one sample phial underthe action of gravity or a vacuum in said at least one sample phial. 14.The method of claim 1, wherein said at least one sample has the samecomposition as the liquid in the pouch.
 15. The method of claim 1,wherein the inlet tube comprises a frangible, and the method comprisesbreaking the frangible to allow the quantity of liquid to flow into thechamber from the pouch.
 16. Apparatus according to claim 6, wherein: theinlet tube includes at least one marking positioned between the distalend and the tube clamp indicative of a preferred area for steriledocking
 17. Apparatus according to claim 16, wherein: the inlet tubeincludes two spaced apart markings positioned between the distal end andthe tube clamp indicative of a preferred area for sterile docking 18.Apparatus according to claim 6, wherein: the sight chamber is tubularand transparent and has an upper end and a lower end; the inlet islocated at the upper end, and the outlet is located at the lower end;the vent is located at the upper end; the sight chamber is marked withgraduations to indicate the volume of liquid therein, the uppermost ofthe graduations being below the inlet and vent.
 19. Apparatus accordingto claim 8, comprising: a port cap mounted for rotation about an axis tothe open end of the sample port; the port cap movable to a closedposition to close the open end; and the port cap comprising a releasablelock adapted to hold it in the closed position, wherein the lockcomprises a first radially extending tab on the open end of the sampleport and a second radially extending tab on the port cap, the tabs beingadapted to engage one another when the port cap is in the closedposition.
 20. Apparatus according to claim 6, wherein the vent has anopening to the environment, and a hinged cap is mounted adjacent theopening, the cap movable between a closed position in which the capblocks the opening and an open position in which the opening isunblocked and positions therebetween in which the opening is partiallyblocked.
 21. Apparatus according to claim 9, wherein the chamber istransparent and rigid.
 22. Apparatus for providing at least one sampleof a liquid contained in a pouch while mitigating the danger ofcontaminating the liquid in the pouch, the apparatus comprising: aninlet tube having proximal and distal ends, and comprising a frangible,the proximal end connected to an inlet of a sterile sight chamber, thechamber comprising: a vent fitted with a bacterial filter through whichair can flow to and from the chamber; and an outlet; the inlet tubecomprising a tube clamp thereon, wherein the tube clamp is a sufficientdistance from the distal end to permit a sterile fluid connection to beestablished with the inlet tube at a point distal to the tube clamp; andthe tube clamp operable to regulate liquid flow through the inlet tubeto the chamber when the connection is established and operable to blockfluid flow in the absence of the connection.
 23. Apparatus according toclaim 22, wherein the chamber is transparent and rigid.
 24. Apparatusaccording to claim 22, wherein the inlet tube comprises a flexiblethermoplastic inlet tube.
 25. Apparatus according to claim 22, whereinthe frangible is between the proximal and distal ends of the inlet tube.26. Apparatus according to claim 22, wherein: the chamber is tubular andtransparent and has an upper end and a lower end; the inlet is locatedat the upper end, and the outlet is located at the lower end; a sampleport is joined to the outlet in a rigid manner so that the sight chambercan be supported substantially upright by a user holding the sample portin one hand while inserting a phial into the open end of the sample portwith the other hand.
 27. Apparatus according to claim 22, wherein: thesight chamber is tubular and transparent and has an upper end and alower end; the inlet is located at the upper end, and the outlet islocated at the lower end; the vent is located at the upper end; thesight chamber is marked with graduations to indicate the volume ofliquid therein, the uppermost of the graduations being below the inletand vent.
 28. Apparatus according to claim 22, wherein the inlet tube isattached to a platelet pouch of an aphaeresis kit.
 29. Apparatus forproviding at least one sample of a liquid contained in a pouch whilemitigating the danger of contaminating the liquid in the pouch, theapparatus comprising: an inlet tube having proximal and distal ends, andcomprising a frangible, the proximal end connected to an inlet of asterile sight chamber that is transparent, the chamber comprising: avent fitted with a bacterial filter through which air can flow to andfrom the chamber; and an outlet; the inlet tube comprising a tube clampthereon, wherein the tube clamp is a sufficient distance from the distalend to permit a sterile fluid connection to be established with theinlet tube at a point distal to the tube clamp; the tube clamp operableto regulate liquid flow through the inlet tube to the chamber when theconnection is established and operable to block fluid flow in theabsence of the connection; and a cup-like sample port having an open endand a tubular peripheral wall connected to the outlet of the chamber ina rigid manner, wherein the open end is opposite the outlet. 30.Apparatus according to claim 29, wherein the inlet tube is attached to aplatelet pouch of an aphaeresis kit.